Sample identification utilizing RFID tags

ABSTRACT

A radio frequency identification (RFID) reader may include a body including a proximal end region, an RF transceiver antenna mounted to the body at the proximal end region, and an RF shield mounted to the body and extending beyond the proximal end region. The RF shield defines an interior space between the body and an open end of the RF shield, and surrounds the antenna. Alternatively, or additionally, a holder of sample containers may provide an RF shield. The reader may be moved into position over a sample container to enable communication between the antenna and an RFID tag associated with the sample container. The RF shield provides isolation from neighboring sample containers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of Application Ser. No. 11/088,539, filed Mar. 24, 2005.

FIELD OF THE INVENTION

The present invention relates generally to sample identification techniques, such as may be desired in conjunction with the handling of one or more individual samples as part of analytical processes. More particularly, the present invention relates to the use of radio-frequency (RF) energy to uniquely identify individual samples and/or containers in which the samples reside.

BACKGROUND OF THE INVENTION

In many processes for analyzing samples, particularly in batch and serial processes where several samples are involved, it is desirable to improve throughput by providing a greater degree of automated control over various stages of the sample handling, preparation, and analysis processes and by providing better management of sample-related data. In one aspect, instrumentation for the handling, preparation and analysis of samples has become more automated. For instance, automated sample handling systems have been developed that include one or more trays holding arrays of vials, test tubes, or multi-well plates containing small quantities of liquid samples. These systems typically include a sampling needle that can be programmed to move to each vial in order to dispense samples into the vials or aspirate samples from the vials. Alternatively, the vials or trays holding the vials may be moved to a sampling needle or other component of the sample handling system. In another aspect, steps have been taken to improve the identification of individual samples. Improvements in sample identification have primarily been made through the utilization of barcode scanning systems. Barcode scanning systems employ an optical barcode scanner that reads a barcode printed on a label. The barcode consists of a combination of dark parallel bars and light spaces between the bars. The barcode scanner reads the barcode by directing a beam of light at the barcode. Because the dark bars of the barcode absorb light and the light spaces reflect light, a detector in the barcode scanner can receive the reflected light signals and convert them into electrical signals, which thereafter can be recognized by electronic means as characters. Barcode labels have been applied to vials and, in the case of multi-well plates, a single barcode label has been applied to a plate.

While barcode systems and other optical techniques may be useful in such applications as the tracking of consumer goods, these types of systems present problems when applied to procedures for handling small liquid-phase samples in conjunction with analytical techniques. The information represented by a barcode is quite limited and fixed. The barcode typically constitutes a short series of characters such as those corresponding to the well-known Uniform Product Code (UPC). Due to the brevity of these character sets, the barcode is capable of identifying only the type of sample or the tray or group of samples of which the sample is a part. When a large number of individual samples are to be handled and analyzed, each of which may be different from the others in terms of composition or other parameters, there are not enough characters in a barcode to adequately distinguish one given sample as being unique from another sample. Even if a barcode were to be employed to uniquely identify a sample as being, for example, Sample #1, that same barcode cannot be used to provide any additional information about that particular sample.

Moreover, because a barcode system depends on optics, it is orientation-sensitive; that is, there is only a finite range of angles between a barcode and a barcode scanner over which optical communication will be successful. When applied to sample handling and analysis systems, the barcode system often requires that several barcode scanners be located at various points along the system in order to adequately track the sample, or that a given barcode-containing vial be transported to a single barcode scanner. Additionally, again due to the use of optics, a barcode-containing vial must be precisely positioned in relation to a barcode scanner to ensure that no other object will interfere with the light path, including neighboring vials. Another related problem stems from the fact that an optical path is easily modified by the presence of substances commonly encountered in sample handling. The smearing of the printed barcode through contact with a researcher or an object, the marring or degradation of the barcode by solvents or other substances, or simply the obstructive presence of fluids or particles on the barcode, all may destroy the ability of the barcode to be accurately read by a barcode scanner.

In view of the foregoing, it would be advantageous to provide a means for uniquely identifying vials and other types of sample containers without the problems attending barcode technology and other known techniques employed in conjunction with sample preparation, handling, and/or analysis. The ability to read an identification code as the vial is accessed for sampling or mixing operations, without moving the vial to another position, would also present significant advantages, in terms of time and chain of custody-type concerns.

SUMMARY OF THE INVENTION

To address the foregoing problems, in whole or in part, and/or other problems that may have been observed by persons skilled in the art, the present disclosure provides apparatus, devices, and methods for uniquely identifying individual analytical samples, as described by way of example in implementations set forth below.

According to one implementation, a radio frequency identification (RFID) reader is provided. The reader comprises a body including a proximal end region, an RF transceiver antenna mounted to the body at the proximal end region, and an RF shield mounted to the body and extending out from the body beyond the proximal end region to an open end of the RF shield. The RF shield defines an interior space between the body and the open end, wherein the antenna is surrounded by the RF shield.

According to another implementation, at least a portion of the RF shield is movable relative to the body.

According to another implementation, a sample holder is provided. The sample holder comprises an RF shield. The RF shield includes a plurality of walls defining a plurality of interior spaces. A sample container is positioned in at least one of the interior spaces. The sample container includes an RFID tag surrounded by one or more of the walls.

According to another implementation, an RFID apparatus is provided. The apparatus includes an RFID reader including an RF transceiver antenna, a sample container including an RFID tag, and an RF shield defining an interior space between the reader and the container. The antenna and the RFID tag are surrounded by the RF shield. In one example of an embodiment of the RFID apparatus, the RF shield is mounted to the reader. In another example, the sample container is positioned in the interior space.

According to another implementation, a method for identifying an object is provided. According to the method, a reader that includes a radio frequency (RF) transceiver antenna is moved into proximity with a sample container whereby the antenna can communicate with a radio frequency identification (RFID) tag of the sample container. The antenna and the RFID tag are surrounded with an RF shield such that the antenna and RFID tag are isolated from an environment external to the RF shield.

According to another implementation of the method, the antenna is employed to read a code stored by the RFID tag whereby the sample container or a sample contained in the sample container can be identified.

According to another implementation, the method further comprises, after reading the code, associating the code with information relating to the identified sample.

According to another implementation of the method, the RF shield is attached to the reader and defines an interior space in which the antenna is located. The reader is moved toward the sample container such that the RFID tag becomes located within the interior space.

According to another implementation of the method, the RFID tag is located in an interior space defined by the RF shield. The reader is moved toward the sample container such that the antenna becomes located within the interior space.

According to another implementation, a sample container includes a container structure extending along a central axis. The container structure encloses an interior and includes an open end. A first cap is mounted to the container structure at the open end and has a first aperture located at the central axis. A second cap is mounted to the first cap and has a second aperture aligned with the first aperture along the central axis. An RFID tag is mounted at the second cap in off-center relation to the central axis. In some implementations, the sample container may further include a closure member mounted at the open end, whereby the interior is isolated from an environment external to the container structure and the first and second apertures provide access to the closure member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of a cross-section of a sample container and sample probe device provided in accordance with an example of one implementation.

FIG. 2 is a top plan view of an RFID tag provided according to an example of one implementation.

FIG. 3 is a top plan view of an RFID tag provided according to an example of another implementation.

FIG. 4 is a schematic view of a sample handling apparatus or system and related components according to an example of one implementation.

FIG. 5 is a flow diagram illustrating a method for uniquely identifying an analytical sample according to an example of one implementation.

FIG. 6 is a schematic view of an example of a sample identifying apparatus or system according to another implementation.

FIG. 7 is a schematic view of an example of a sample identifying apparatus or system according to another implementation.

FIG. 8 is a cross-sectional view of an example of a sample identifying apparatus or system in which differently shaped sample containers are illustrated.

FIG. 9 is a top plan view of an RFID tag provided according to an example of another implementation.

FIG. 10 is a side elevation view of the RFID tag illustrated in FIG. 9.

FIG. 11 is a schematic view of an arrangement of sample containers including RFID tags.

FIG. 12 is a schematic view of another arrangement of sample containers including RFID tags.

FIG. 13 is a front elevation view of a cross-section of a sample container provided in accordance with an example of another implementation.

DETAILED DESCRIPTION OF THE INVENTION

In general, the term “communicate” (for example, a first component “communicates with” or “is in communication with” a second component) is used herein to indicate a structural, functional, mechanical, electrical, optical, magnetic, ionic or fluidic relationship between two or more components or elements. As such, the fact that one component is said to communicate with a second component is not intended to exclude the possibility that additional components may be present between, and/or operatively associated or engaged with, the first and second components.

The subject matter disclosed herein generally relates to the handling of one or more individual samples as, for instance, may be performed as part of or in preparation for a sample analysis process. The subject matter provides for the unique identification of individual samples so that one sample may be readily distinguished from another sample and that once identified, the identity of the sample may be correlated with additional information uniquely pertaining to that sample. Accordingly, systems, apparatus, and methods disclosed herein may be particularly beneficial in applications entailing the analysis of several individual samples simultaneously or serially in a given test run, where one or more samples may be different from other samples, and where one or more components of the system or apparatus may be partially or fully automated. The approach toward identification of samples disclosed herein makes use of RF energy and therefore does not rely on optical energy and is not limited by optics-related problems. Examples of implementations of apparatus, systems, devices, and/or related methods for sample identification and sample handling are described in more detail below with reference to FIGS. 1-13.

FIG. 1 is a front elevation view of a cross-section of a sample handling apparatus or system 100 provided with sample identification functionality in accordance with an example of one implementation. Sample handling apparatus 100 operates in conjunction with a sample container 110. In some implementations, sample handling apparatus 100 may be considered as comprising sample container 110. That is, in some implementations, sample container 110 may be considered as being part of sample handling apparatus 100.

Sample container 110 may be any container suitable for containing an analytical sample, particularly a liquid-phase or multi-phase sample for which one or more quantitative and/or qualitative analyses are desired. Examples of sample containers 110 include, but are not limited to, vials, test tubes, cuvettes, wells, flow-through cells, and the like. In the example illustrated in FIG. 1, sample container 110 includes a first structure or container structure 112 that defines the interior of sample container 110 in which an individual sample may reside. Container structure 112 may include one or more side walls 114, a closed bottom end 116, and an open top end 118. Typically, container structure 112 is generally cylindrical in shape, but in alternative implementations may have a polygonal profile of any suitable type. Container structure 112 may be constructed from glass, plastic, or any other material suitable for containing analytical samples. Container structure 112 may include an end member or cap 120 mounted to a surface of container structure 112 at its open end 118. Cap 120 may be attached to container structure 112 by crimping, threading, or any other suitable means. In some implementations, cap 120 includes an aperture 122 that typically is centrally located relative to a central, longitudinal axis 123 of container structure 112.

Generally, no limitation is placed on the size of container structure 112 or its capacity for holding a volume of sample material. In some implementations, container structure 112 may enclose an interior that has a volume ranging from approximately 0.1 mL to approximately 1000 mL. In other implementations, the volume may range from approximately 0.1 mL to approximately 100 mL. In other implementations, the volume may range from approximately 1 mL to approximately 50 mL. In other implementations, the volume may range from approximately 2 mL to approximately 20 mL.

Container structure 112 may also include a closure member 124, for example a septum or plug, that is attached or mounted to container structure 112 so as to close off its open end 118 and thereby isolate or seal the interior of sample container 110 from the ambient environment. As appreciated by persons skilled in the art, closure member 124 may be composed of a resilient or deformable material that enables closure member 124 to perform its isolating function, as well as to be pierced by a needle without impairing its ability to provide isolation. In some implementations, closure member 124 is secured to container structure 112 by press-fitting, which may be facilitated by the installation of cap 120 onto container structure 112. The aperture 122 of cap 120 provides external access to closure member 124 so that a needle or the like may be inserted through closure member 124 and into container structure 112. In some implementations in which closure member 124 is not needed, sample container 110 is employed in an open mode, in which case the aperture 122 of cap 120 provides direct access to the interior of sample container 110.

In some implementations, container structure 112 may have open ends at both the top and the bottom, and closure members and/or caps at both the top and the bottom. Examples of these container structures include purge and trap vials commercially available from Varian, Inc., Palo Alto, Calif., and typically are employed for soil analysis or other types of environmental analysis. In some implementations, sample container 110 may include a magnetic stirring or agitating element such as a bar or bead.

For purposes of the present disclosure, no limitation is placed on the composition of the sample or its properties (for example, molecular weight, polarity or non-polarity, ionic, volatility, temperature, or the like), or on the manner in which the sample is provided to sample container 110. In a typical implementation, the sample provided to sample container 110 is predominantly a liquid but in other implementations may be a multi-phase mixture. For example, the sample may be a solution, emulsion, suspension or mixture in which analyte components (for example, molecules of interest) are initially dissolved in one or more solvents or carried by other types of components. In some implementations, particularly those associated with headspace sampling techniques and which in turn may be associated with gas chromatography (GC) or solid-phase micro-extraction (SPME), sample container 110 may contain a vapor above a liquid or solid. In such techniques, it is the vapor that typically is sampled, and hence the vapor may be considered to be the sample or part of the sample. Accordingly, terms such as “sample” or “sample material” as used herein are not limited by any particular phase, form, or composition. Generally, however, the sample contains analytes of the type that are amenable to qualitative and/or quantitative instrumental techniques of analytical chemistry such as, for example, the various types of chromatography, dissolution, mass spectrometry, spectroscopy, nuclear magnetic resonance (NMR) spectrometry or imaging, calorimetry, and the like. The sample may be dispensed into sample container 110 or removed from sample container 110 either manually or by automated means.

In accordance with implementations described in this disclosure, sample container 110 includes a second structure that supports a device for storing information uniquely pertaining to the sample contained within sample container 110. This device, which may be referred to as a radio-frequency identification (RFID) tag 126, transponder, smart label, or smart chip, is described in more detail below. In the example illustrated in FIG. 1, RFID tag 126 is positioned with cap 120 such that cap 120 serves as the second structure supporting RFID tag 126. In other implementations, as can be readily appreciated from FIG. 1, RFID tag 126 may alternatively be positioned with closure member 124 such that closure member 124 serves as the second structure supporting RFID tag 126. RFID tag 126 may be positioned with cap 120 or closure member 124 in any suitable fixed manner. As examples, RFID tag 126 may be attached or mounted to cap 120 or closure member 124 through the use of an adhesive backing or glue, or may be integrated with cap 120 or closure member 124 by any suitable fabrication process. In other implementations, RFID tag 126 may be attached directly to container structure 112. In other implementations, RFID tag 126 may be attached directly to container structure 112 at or near the bottom of container structure 112 instead or at or near open end 118 at the top. For instance, RFID tag 126 may be attached to a side wall 114 or centered at closed bottom end 116 of container structure 112. In implementations where a multi-well plate is provided that contains a plurality of wells corresponding to an array of container structures 112, a plurality of RFID tags 126 may be respectively positioned at the centers of corresponding bottom ends 116. In still other implementations in which container structure 112 has opposing open ends and closure members and/or caps at both the top and the bottom, RFID tag 126 may be attached or mounted to the closure member or the cap that is located at the bottom of container structure 112, in which case the second structure would correspond to the closure member or the cap located at the bottom.

Sample handling apparatus 100 may be any apparatus that can function to transfer a sample to and/or from sample container 110, and/or transfer a probe of any suitable type into and/or out from sample container 110 such as, for example, a sample-absorbing wick or fiber, an optical probe, a temperature probe, a stirrer or agitator, or the like. In the present context, the term “transfer” is intended to encompass dispensing or loading a sample (or a portion of a sample) into sample container 110, aspirating or removing a sample (or a portion of a sample) from sample container 110, or both, or inserting a probe into sample container 110 or removing a probe from sample container 110. For any of these purposes, sample handling apparatus 100 includes a sample transfer or probe device 130 that is movable toward and away from sample container 110, and hence toward and away from RFID tag 126. Accordingly, the term “sample probe device” may encompass a sample transfer device or a probe transfer device. The mobility of sample probe device 130 may be fully automated or semi-automated. Moreover, one or more components of sample probe device 130 may be movable in one, two, or three dimensions. The portion of sample probe device 130 illustrated in FIG. 1 may represent a movable member 132, such as a probe head or carriage or a needle-mounting head, provided with sample handling apparatus 100. As appreciated by persons skilled in the art, a movable member 132 of this type may be driven by components provided with sample handling apparatus 100 such as, for example, a robotic assembly or one or more motors, actuators, linkages, guide means, and the like.

Sample probe device 130 may also include a sample probe 134 that may be adapted to carry out one or more functions or operations. In the example illustrated in FIG. 1, sample probe device 130 is adapted for handling liquid samples and thus may be characterized as a sample transfer device. Accordingly, the sample probe 134 associated with sample probe device 130 may be provided in the form of a sample conduit through which a sample may be transferred to or from sample container 110. Sample probe 134 may be supported by or attached to movable member 132. Examples of a sample probe 134 include, but are not limited to, a capillary, needle, tube, pipe, pipette, cannula, hollow probe, sensing, detecting or measuring instrument (for example, a dip probe or camera), stirrer, and the like. In some implementations, sample probe device 130 is able to insert sample probe 134 into sample container 110. In implementations where sample container 110 includes closure member 124, sample probe 134 may be structured so as to be able to pierce through and penetrate closure member 124 to access the interior of sample container 110. Sample probe 134 extends, or is extendable, out from a lower end region 136 of sample probe device 130. Sample probe device 130 may include a sample probe guide 138 positioned at lower end region 136 to support and/or guide sample probe 134. Sample probe 134 may be fixed relative to sample probe device 130 or to at least that portion of sample probe device 130 shown in FIG. 1, in which case sample probe device 130 may be lowered toward sample container 110 in order to insert sample probe 134 into sample container 110. Alternatively, sample probe 134 may be movable relative to sample probe device 130 for extending sample probe 134 into and out from sample container 110. In either case, sample probe guide 138 maintains sample probe 134 in a proper position or alignment with respect to lower end region 136.

In some implementations, sample probe 134 may be a hollow sheath that contains a sample-absorbing fiber. This fiber may be extended into a liquid sample contained in sample container 110 (for example, in SPME techniques) or into a vapor contained in sample container 110 above the liquid or solid (for example, in headspace SPME techniques). The fiber absorbs compounds of interest from the liquid or vapor and is then retracted into the sheath. The sheath is then drawn out from sample container 110. The sheath may function as a needle so that it is able to pierce a closure member 124 while protecting the fiber. In other implementations, sample probe 134 may be adapted to perform some type of analysis, detection, or measurement. Accordingly, sample probe 134 may be, for example, an optical probe or a temperature-sensing probe. Alternatively, sample probe 134 may also include the afore-mentioned sheath that is adapted for piercing a closure member 124 while protecting this type of probe.

Sample probe device 130 further includes a radio-frequency (RF) transceiver antenna 150 for communicating with RFID tag 126 of sample container 110. In some implementations, RF transceiver antenna 150 advantageously is positioned at or near a lowermost part of lower end region 136 of sample probe device 130 for communicating with RFID tag 126 at close range, and in some implementations may even contact RFID tag 126 although contact is not required. This configuration ensures that RF transceiver antenna 150 will come into close proximity with RFID tag 126 (for example, a few millimeters) when sample probe device 130 is moved into position over sample container 110. As appreciated by persons skilled in the art, the sensitivity of RF transceiver antenna 150 and/or the electronics with which it communicates can be adjusted for close-range communication with RFID tag 126. In the present context, this configuration ensures that RF transceiver antenna 150 is able to discriminate the RFID tag 126 of one sample container 110 from the RFID tag 126 of another, nearby sample container 110. That is, when sample probe device 130 is positioned over sample container 110, RF transceiver antenna 150 should be able to read the RFID tag 126 of that particular sample container 110 and not an RFID tag 126 provided with any other sample container 110. Moreover, RF transceiver antenna 150 may be utilized to sense whether a particular sample container 110 is missing from an array of sample containers or contains no RFID tag 126. For any of these purposes, as shown in the example illustrated in FIG. 1, RF transceiver antenna 150 may be mounted to sample probe guide 138.

In some implementations, also shown in the cross-sectional view of FIG. 1, RF transceiver antenna 150 and RFID tag 126 may be substantially centered about sample probe 134 and/or central longitudinal axis 123 of sample container 110 so as to be generally aligned with each other. For instance, both RF transceiver antenna 150 and RFID tag 126 may comprise respective annular RF transmitting components such as conductive loops that are generally aligned with each other. These loops may be positioned concentrically relative to sample probe 134 and/or central longitudinal axis 123 of sample container 110, and lie along planes parallel to the top of sample container 110. Implementations utilizing conductive loops may enhance the selectivity with which RF transceiver antenna 150 is able to read RFID tag 126, particularly at certain frequencies.

Generally, RFID tag 126 may be any device capable of storing data and transmitting the data via an RF carrier signal in response to a query from a suitable reader, such as an RF-based query transmitted by an RF transceiver antenna 150. For example, RFID tag 126 may be realized by forming an integrated circuit on a suitable substrate such as a silicon chip. The chip in turn may be provided on a flexible substrate such as a label or adhesive sticker. In some implementations, RFID tag 126 may also include a small, typically flexible antenna interconnected to the integrated circuit or chip to enable RFID tag 126 to transmit RF signals to a suitable reader such as RF transceiver antenna 150. In other implementations, electrical contacts or interconnects provided with RFID tag 126 may serve the same purpose as an antenna in which case a discrete antenna need not be fabricated with RFID tag 126.

RFID tag 126 may be passive, active, or semi-passive. As can be appreciated by persons skilled in the art, a passive RFID tag 126 does not require a power source for its operation. A passive RFID tag 126 can absorb some of the electromagnetic energy from a signal sent by RF transceiver antenna 150 and reflect the energy as an RF return signal that carries the coded information stored in its memory. For example, an RF scan transmitted by RF transceiver antenna 150 may induce electrical current in the antenna or contact of RFID tag 126, thereby providing enough power for RFID tag 126 to respond properly. On the other hand, active RFID tags and battery-assisted passive RFID tags (or semi-passive RFID tags) require a battery or other suitable power source. In battery-assisted passive RFID tags, a battery is employed to provide power for operation of the chip but not for communicating with RF transceiver antenna 150. The powered (active and semi-passive) RFID tags typically have longer operating ranges and greater capacity for data storage than passive RFID tags, but cost more and may have much shorter operating lives. The physical dimensions of a passive or active RFID tag may be in the micron or millimeter range. Typically, a passive RFID tag will be smaller than an active RFID tag.

RFID tag 126 and RF transceiver antenna 150 may operate within any suitable range of radio frequencies, including low-frequency or LF (typically considered as including the range of approximately 125-134 kHz), high-frequency or HF (typically 13.56 MHz or thereabouts), ultra-high frequency or UHF (typically considered as including the range of approximately 868-956 MHz) and microwave (for example, 2450 MHz). Each frequency or range of frequencies may have advantages or disadvantages depending on the particular implementation, as well as factors such as intended read range, operating environment, power requirements, costs of materials and fabrication, geometry, and the like. For purposes of the implementations disclosed herein, the frequency utilized for operation is one that is compatible with close-range, error-free communication, i.e., typically in the range of a few millimeters as previously noted.

The chip provided with RFID tag 126 may have read-write or read-only capability. When equipped with a read-write chip, new information can be added to RFID tag 126 or written over existing information. When equipped with a read-only chip, the information stored by RFID tag 126 cannot be changed unless the chip is reprogrammed. As appreciated by persons skilled in the art, the read-only chip of RFID tag 126 may include electrically erasable programmable read-only memory (EEPROM).

The data recorded by and stored on RFID tag 126 includes enough information to uniquely identify the sample residing in sample container 110 so that sample container 110 and/or its sample can be discriminated from other sample containers 110 and/or their respective samples. Generally, the code is long enough to enable each RFID tag 126 employed in a given system or procedure to have a unique identity for purposes of tracking through the system, correlation with other data, and the like. As a few examples, the size of the code may be 64 bits or 96 bits, although in other implementations the code may be larger or smaller. In the case where the code is employed simply as a unique identifier for a sample contained in a sample container 110, the code may be associated with an address in a remote memory where more detailed information regarding the sample has been stored, such as in a database stored on a computer provided with or communicating with sample handling system 100. For example, once the code has been read by RF transceiver antenna 150, the code may then used to search the database for more detailed information specifically relating to the individual sample identified by the code. The types of information with which the code may be associated may depend on many factors, such as the type of analysis or analyses to be performed on samples or the types of analytical instrumentation to be employed. The types of information may include, but are not limited to, the composition and properties of the sample (to the extent known), the origin of the sample (for example, a particular test site, specimen, patient, or the like), the date and time the sample was taken or prepared, the conditions under which the sample was prepared, the types of reagents, solvents, additives or chemical labels combined with the sample, the position (for example, row/column) of the sample container 110 within an array of sample containers 110, the identity of the particular group of sample containers 110 with which the sample container 110 is arranged (for example, a vial rack or tray, multi-well plate, or the like), and the like. Depending on the storage capability of RFID tag 126, one or more of these types of data may be directly stored in RFID tag 126 along with its identification code.

FIG. 2 illustrates one example of an RFID tag 200 that may be utilized in conjunction with implementations described herein. RFID tag 200 includes a microchip 210 in which data including the unique identifier code, and alternatively other data as well, may be recorded and stored. One or more electrically conductive members 212 and 214 may be connected in electrical communication with microchip 210. In the illustrated example, two conductive members 212 and 214 are utilized and are provided in the form of flat metal plates. Conductive members 212 and 214 are attached to a substrate 216, which may be non-conductive. Microchip 210 is attached to conductive members 212 and 214 or directly to substrate 216 between conductive members 212 and 214. As shown in FIG. 2, conductive members 212 and 214 may be shaped such that RFID tag 200 may be characterized as having a bow-tie configuration. One or more antennas 218 and 220 may be connected to conductive members 218 and 220, respectively. Antennas 218 and 220 may have arcuate shapes such as substantially semicircular shapes. A thin conductive strip 222 may interconnect the ends of antennas 218 and 220 opposite to conductive members 212 and 214 to prevent static charge buildup that might damage microchip 210. Antennas 218 and 220 may be centered relative to axis 123 (FIG. 1). In alternative implementations, conductive members 212 and 214 may themselves serve as the antennas for RFID tag 200, in which case antennas 218 and 220 are not needed. An RFID tag 200 configured as illustrated in FIG. 2 may be particularly advantageous when operating at UHF.

FIG. 3 illustrates another example of an RFID tag 300 that may be utilized in conjunction with implementations described herein. RFID tag 300 generally has an annular, ring, or loop configuration. In some implementations, as shown for example in FIG. 1, RFID tag 126 may have a loop configuration similar to RFID tag 300 shown in FIG. 3, and may be utilized in conjunction with an annular RF receiver antenna 150 (FIG. 1). In these implementations, RF receiver antenna 150 and RFID tag 126 are concentric with sample probe 134 and sample container 110, which may increase the selectivity of the RFID system as previously noted. As shown by example in FIG. 3, RFID tag 300 may include a coiled antenna 302 attached by any suitable means to a microchip 304. Antenna 302 may include one or more loops of conductive wire, ribbon or other suitable material. Antenna 302 may be coated with or enclosed by an insulating material if appropriate. An RFID tag 300 configured as illustrated in FIG. 3 may be particularly advantageous when operating at frequencies lower than UHF such as, for example, HF.

FIG. 4 schematically illustrates an example of an automated sample handling apparatus or system 400 that includes the RFID functionality described above. Sample handling system 400 may include a sample holding assembly 410 that may in turn include one or more sample holding modules 412, 414, 416 and 418. While four sample holding modules 412, 414, 416 and 418 are specifically illustrated, more or less may be provided. Sample holding modules 412, 414, 416 and 418 may be provided in the form of racks or plates that include an array of apertures in which sample containers 110 can be mounted, typically in an upright (vertical) fashion. Sample containers 110 may be configured in the manner illustrated in FIG. 1. Alternatively, or additionally, sample holding assembly 410 may include a tray that supports the bottoms of sample containers 110 or sample holding modules 412, 414, 416 and 418. As another alternative, sample holding modules 412, 414, 416 and 418 may be provided in the form of multi-well plates, such as microtitre plates, in which sample containers 110 are formed as an array of wells or depressions in blocks of suitable material (for example, plastic or quartz). Still further, while in the presently described implementation sample holding assembly 410 provides for a generally rectilinear array (for example, rows and columns) of sample containers 110, it is readily appreciated that in other implementations sample holding assembly 410 may include a carousel that provides a rotary arrangement of sample containers 110.

Sample handling apparatus 400 may additionally include a mobile sampling assembly such as a robotic assembly 430. Robotic assembly 430 supports a movable member 132 such as a sample probe mounting device or carriage device, which may be configured as a sample probe device 130 and include a sample probe 134 as described above in conjunction with FIG. 1. As indicated schematically in FIG. 4 by arbitrarily designated X-, Y- and Z-axes, robotic assembly 430 is capable of moving sample probe 134 along one, two, or three dimensions (and typically at least two dimensions) as needed for positioning sample probe 134 into operational alignment with each sample container 110 or selected sample containers 110 that have been loaded into sample handling system 400. By this configuration, sample handling apparatus 400 is able to transfer selected samples (or portions of samples) to and/or from corresponding sample containers 110 in the case where sample probe 134 is a sample conduit. In the case where sample probe 134 is a probe of the analyzing, measuring, sensing, or detecting type, sample handling apparatus 400 is able to move this type of probe into and/or out from selected sample containers 110 when needed. In some implementations, sample handling apparatus 400 may include both probes of the sample-transferring type and probes of the analytical function type, and an RF transceiving antenna 150 may be provided in cooperation with one or both types of probes.

Sample probe device 130 is movably connected to another movable member 432 so as to be movable within a guide means such as a track 434 of movable member 432 along the Z-axis. In alternative implementations, sample probe 134 may itself be movable relative to a mounting structure of robotic assembly 430. Movable member 432 in turn is movably connected to a guide means such as an arm 436 or similar structure such that movable member 432 is movable along the X-axis. Arm 436 in turn is movably connected to another guide means such as an arm 438 such that arm 436 is movable along the Y-axis. Motors or actuators (not shown) responsible for the movement of these components in the various directions may be programmed so that sample probe 134 is positionable over designated sample containers 110 according to any desired sequence.

Sample probe 134 may communicate with other fluid circuitry typically provided with sample handling system 400. In FIG. 4, the other fluid circuitry is generally represented by block 450 and may include, for example, valves, tubing, sample loops, pumps, solvent and reagent reservoirs, rinsing stations, dilution modules, mixing chambers, waste receptacles, and the like as is readily appreciated by persons skilled in the art. Fluid communications between fluid circuitry 450 and sample probe 134, and between fluid circuitry 450 and any analytical instrument or instruments 460 that may be provided, are schematically depicted by lines 462 and 464, respectively.

Sample handling system 400 may further include electronic circuitry 470 for controlling the various operations of sample handling system 400. Electronic circuitry 470 may include hardware control circuitry 472 that is conventionally associated with sample preparation and liquid handling instrumentation. For example, hardware control circuitry 472 may control the operations of the various components of robotic assembly 430 and fluid circuitry 450. As another example, hardware control circuitry 472 may control the sequential injections of samples into analytical instrument 460 or combination of analytical instruments such as, for example, those associated with chromatography, spectroscopy, mass spectrometry, nuclear magnetic resonance spectrometry, calorimetry, and the like. Accordingly, hardware control circuitry 472 is schematically illustrated as electrically communicating with robotic assembly 430, fluid circuitry 450, and analytical instrument 460 via lines 474, 476, and 478, respectively. Electronic circuitry 470 may be programmable for all such purposes, such as through the execution of software and/or in response to user input via a suitable peripheral device.

In the example illustrated in FIG. 4, electronic circuitry 470 is shown to also include an RF signal processing circuit 480 that communicates with RF transceiver antenna 150 to receive code-bearing signals detected from RFID tags 126 and process the signals as digital information. Particularly in implementations in which RFID tags 126 are passive, RF signal processing circuit 480 may function to produce the RF signal that is transmitted by RF transceiver antenna 150 to activate RFID tags 126 in order to acquire their respective coded information. RF signal processing circuit 480 may be interfaced by any suitable means with hardware control circuitry 472, as well as with any data acquisition software provided with analytical instrument 460, so that their respective operations and functions are coordinated as needed. Electronic circuitry 470 is further shown to include memory 484 for storing a database containing information associated with the codes transmitted by RFID tags 126. Memory 484 may be provided in any suitable format and may be interfaced with removable storage media.

It will be understood that hardware control circuitry 472, RF signal processing circuit 480, and sample information-containing memory 484 are illustrated in FIG. 4 as being integrated as a single schematic block (electronic circuitry 470) by way of example only. The various functions described here may be implemented in separate modules, including computers, function- or application-specific electronic processing devices, remote servers, and the like. As one example, a programming station 490 by which codes are recorded in RFID tags 126 may also be configured to allow a user to initially populate the database containing information associated with each code. In this implementation, the contents of the database may thereafter be transferred to memory 484 in electronic circuitry 470 via a suitable communication line 492 or by removing storage media from programming station 490 and then loading the media into memory 484. Moreover, communications between electronic circuitry 470 and robotic assembly 430, fluid circuitry 450, analytical instrument 460, and programming station 490 are represented by lines 474, 476, 478, and 492, respectively, for the sake of simplicity. In practice, these lines 474, 476, 478, and 492 may represent one or more signal paths as needed for communications, and may represent hard wiring and/or airborne, wireless signals.

Referring now to FIG. 5, and with reference to the various implementations described above and illustrated in FIGS. 1-4, an example of a method for uniquely identifying an analytical sample will now be described. A sample container 110 that includes an RFID tag 126 (or 200, or 300) is provided. Sample container 110 and its RFID tag 126 may be configured or designed in accordance with one or more of the examples of implementations described elsewhere in this disclosure. RFID tag 126 contains information relating to a sample contained in sample container 110. As described above, the sample information may include a code that serves as a unique identifier for the sample and/or the sample container 110 in which the sample resides. The sample information may additionally include other data relating to the sample, such as features, properties, constituents, origin, conditions under which the sample was prepared, and the like as described above. In some implementations of the method, a plurality of sample containers 110 equipped with RFID tags 126 are provided. The plurality of sample containers 110 may be arranged in an ordered array such the respective positions of the sample containers 110 can be defined. A sample probe device 130 that includes a sample probe 134 and an RF transceiver antenna 150 is also provided. Sample probe device 130 may be configured or designed in accordance with one or more of the implementations described above. The plurality of sample containers 110 may be positioned with a sample handling apparatus or system 100 or 400 that has one or more automated features or components such as described above.

At block 510 in FIG. 5, sample probe device 130 is moved into proximity with a sample container 110. That is, sample probe device 130 is moved into a position relative to sample container 110 such that RF transceiver antenna 150 is close enough to RFID tag 126 of sample container 110 to enable the coupling of RF energy between RF transceiver antenna 150 and RFID tag 126. In other words, as a result of movement of sample probe device 130, RFID tag 126 falls within the RF transmission range of sample probe device 130. This range is close enough to ensure that RF transceiver antenna 150 communicates with the intended sample container 110 and not with any other neighboring sample container 110, and without interference with any other neighboring sample container 110. In particularly desirable implementations, this range is a close range, for example 0-10 mm. In some implementations such as described above, the position into which sample probe device 130 is moved relative to sample container 110 is a position directly above sample container 110 where RF transceiver antenna 150 is generally aligned with RFID tag 126. RF transceiver antenna 150 broadcasts an activation or query signal so as to be able to scan for one or more sample containers 110. RF transceiver antenna 150 may broadcast its signal on a continuous basis or at regular intervals. Alternatively, the broadcasts by RF transceiver antenna 150 may be coordinated or synchronized with the movement of sample probe device 130 (and thus RF transceiver antenna 150), such that RF transceiver antenna 150 transmits its signal only upon reaching its final position relative to the targeted sample container 110. In implementations where a plurality of sample containers 110 are provided, the movement of sample probe device 130 may follow a predetermined or programmed path from one sample container 110 to another. For example, sample probe device 130 may be coupled to a programmable robotic assembly 430 provided with a sample handling apparatus 400, as described above.

At block 520 in FIG. 5, RF transceiver antenna 150 reads sample data stored by the RFID tag 126 of the target sample container 110. As a result, the sample contained in sample container 110 is identified and, consequently, may be readily distinguished from other samples that are the subjects of the sample handling, preparation and/or analysis processes being performed. Depending on the amount and types of sample data stored on a given RFID tag 126 interrogated by RF transceiver antenna 150, RF transceiver antenna 150 may forward the data acquired to suitable electronic circuitry such as a microprocessor (operating, for example, within electronic circuitry 470 shown in FIG. 4). The electronic circuitry may interface with a database to associate the sample data acquired by RF transceiver antenna 150 with additional (and typically more detailed) data pertaining to the sample that has just been identified. The accessing of a database, look-up table, or the like is particularly useful in implementations where the sample data retrieved from an RFID tag 126 is merely a code that uniquely identifies the sample. In some implementations, once an RFID tag 126 of a sample container 110 has been read, the sample may be transferred to one or more analytical instruments 460 for analysis.

In some implementations, the method just described and illustrated in FIG. 5 may constitute a single iteration, and hence may be repeated for other sample containers 110 that are being processed.

In some implementations, RF transceiver antenna 150 may be utilized to determine whether a particular position within or relative to a sample handling apparatus or system 100 or 400 is occupied by a sample container 110, or whether a sample container 110 is missing from that particular position, or whether a sample container 110 occupying that particular position lacks an RFID tag 126 or has a defective RFID tag 126. The RF-related components as disclosed herein allow such operations even in the presence of other RFID-tagged sample containers occupying neighboring positions in close proximity to the presently targeted position. In still other implementations, RF transceiver antenna 150 may be utilized to scan an entire array of sample containers 110 (see, for instance, sample holding assembly 410 and associated components illustrated in FIG. 4), not only to acquire sample data but also to compile a list of sample containers 110 that are present or absent at the various positions of the array. This scan may or may not involve momentarily stopping RF transceiver antenna 150 over each target sample container 110 or sample container site. Again, the RF-related components as disclosed herein allow such operations to be carried out accurately at each targeted position without neighboring sample containers 110 interfering with the operations.

In some implementations, sample probe 132 may perform an analytical function or operation while located at a given sample container 110, and this function or operation may be executed before or after RF transceiver antenna 150 reads the data from RFID tag 126, or while the data is being read. Examples of analytical functions or operations that may be performed by sample probe 132 may include analytical, detecting, or measuring tasks such as, optical detection, temperature measurement, or the like.

FIG. 6 schematically illustrates an RFID apparatus or system 600 according to another implementation. The RFID apparatus 600 may include or be part of a sample handling apparatus such as, for example, described above and illustrated in FIG. 1 or 4. RFID apparatus 600 includes an RFID reader device 604. The reader 604 may include or be part of a sample transfer or probe device such as, for example, described above and illustrated in FIG. 1 or 4. The reader 604 includes a main body 608 having a proximal end region 612 and a distal end region 616. An RF transceiver antenna 620 is mounted by any suitable means to the body 608 at the proximal end region 612. The RF transceiver antenna 620 may be mounted on any portion of the proximal end region 612, such as on a side 624 of the body 608 or, as illustrated by example in FIG. 6, on a lowermost end 628 of the body 608. As described above for other implementations, the reader 604 may be a mobile device and the mobility may be manual or automated. For example, the reader 604 may be part of or under the control of a robotic or automated device. The reader 604 may include RF processing circuitry 630 located within the body 608 in communication with the RF transceiver antenna 620, in which case the reader 604 may be considered as an RF transceiver. Alternatively, RF processing circuitry may be provided remotely from the reader 604 (see, e.g., the RF signal processing circuit 480 of FIG. 4) and, for instance, communicate with the RF transceiver antenna 620 through wiring routed through the body 608 or by any other suitable electrical communication means.

As further illustrated in FIG. 6, RFID apparatus 600 includes an RF shield 632 mounted to the body 608. The RF shield 632 extends from the body 608 for a distance beyond the lowermost end 628. The RF shield 632 may have any shape suitable for defining an interior space 636 such that the RF shield 632 terminates at an open end 640. For instance, the RF shield 632 may be generally cylindrical such that its cross-section is generally circular or elliptical, or may be rectilinear or polygonal. As additional examples, the RF shield 632 may be shaped as a box, cup, dome, cone, cap, or bell. For defining the interior space 636, the RF shield 632 may include a continuous wall 644 or a plurality of adjoined walls 644. The interior space 636 is generally defined within the confines of the wall(s) 644 of the RF shield 632, and between the proximal end region 612 of the body 608 and the open end 640 of the RF shield 632. Thus, the RF transceiver antenna 620 is positioned within the interior space 636. The wall(s) 644 may be constructed from any material suitable for impeding the transmission of RF energy through the wall(s) 644. Non-limiting examples of suitable materials for the wall(s) 644 include, but are not limited to, electrically conductive materials such as various metals, as well as certain ceramics and polymers. As appreciated by persons skilled in the art, the material utilized for RF shield 632 may depend on the frequency range within which an RFID tag operates. In the case of a conductive metal, RF shield 632 may be mounted to body 608 such that the shielding material is grounded to improve the shielding function.

Also illustrated in FIG. 6 is a sample holder 650 that includes one or more sample holding units. In the illustrated example, three sample holding units 654, 658 and 662 are shown with the understanding that more or less sample holding units may be provided. The sample holder 650 may represent one or more sample containers such as, for example, described above and illustrated in FIG. 1 or 4. In this implementation, each sample holding unit 654, 658 and 662 may represent an individual sample container. Each sample container includes a respective RFID tag 666, 670 and 674 such as, for example, described above and illustrated in FIGS. 1-4. In another implementation, the sample holder 650 may represent a sample holding assembly such as, for example, described above and illustrated in FIG. 4. In this latter implementation, each sample holding unit 654, 658 and 662 may represent an individual sample container or multi-well plate supported by the sample holding assembly, or a sample holding module or compartment (e.g., rack, plate, tray, etc.) for supporting one or more sample containers. In the latter implementation, respective RFID tags 666, 670 and 674 may be affixed to individual sample containers, individual wells of a multi-well plate, individual multi-well plates, or individual sections or modules of the sample holding assembly.

The provision of the RF shield 632 may be desirable in implementations where the respective RFID tags associated with separately identifiable items or objects are in very close proximity to each other, the respective positions of the RFID tags relative to their corresponding items are inconsistent from one item to the next item, and/or the position of the RFID tag of one or more items is not accurately known. In such situations, the possibility exists that the RF transceiver antenna 620 will pick up a signal from items other than the item of interest.

For example, FIG. 6 illustrates a situation in which the RFID tags 666, 670 and 674 of the respective sample holding units 654, 658 and 662 are not uniformly positioned. For example, the RFID tag 666 of the leftmost sample holding unit 654 is positioned at or near the center of the sample holding unit 654, the RFID tag 670 of the central sample holding unit 658 is positioned at or near the rightmost edge of the sample holding unit 658, and the RFID tag 674 of the rightmost sample holding unit 662 is positioned at or near the leftmost edge of the sample holding unit 662. In this example, it is desired to acquire the information stored in the RFID tag 670 of the central sample holding unit 658. Accordingly, the reader 604 has been positioned directly over the central sample holding unit 658 such that the antenna 620 is in close proximity with the RFID tag 670 of the central sample holding unit 658. As described above, this positioning may be accomplished by moving the reader 604 to the central sample holding unit 658, moving the sample holding unit 658 to the reader 604 or, in the case of a sample holder 650 containing a plurality of sample holding units 654, 658 and 662, moving the sample holder 650 such that the central sample holding unit 658 is positioned directly under the reader 604.

Of particular interest in this example is the relatively close proximity of the respective RFID tags 670 and 674 of the center and rightmost sample holding units 658 and 662 to each other. In such a situation, it is possible for the reader 604 to pick up a signal from the RFID tag 674 of the rightmost sample holding unit 662, or for a signal from the RFID tag 674 of the rightmost sample holding unit 662 to otherwise interfere with the desired communication between the reader 604 and the RFID tag 670 of the central sample holding unit 658. Due to the close proximity of the RFID tags 670 and 674, it is likely that the RFID tag 674 will provide a signal of similar magnitude to the signal provided by the RFID tag 670 such that the RF processing circuitry 630 associated with the reader 604 may have difficulty discriminating between the two signals and selectively reading the target RFID tag 670.

Several problems may arise from erroneous communication between the reader 604 and a neighboring RFID tag (e.g., the RFID tag 674 of the rightmost sample holding unit 662) instead of or in addition to intended communication between the reader 604 and a target RFID tag (e.g., the RFID tag 670 of the central sample holding unit 658). As a few examples, the reader 604 may acquire information from the wrong sample holding unit, the reader 604 may erroneously identify a neighboring sample holding unit as being the target sample holding unit of interest, the reader 604 may determine an incorrect position of the target sample holding unit, the reader 604 may erroneously determine that the target sample holding unit is present or absent when in fact it is a neighboring sample holding unit that is present or absent, etc.

As demonstrated in FIG. 6, however, the possibility of such problems is eliminated or least greatly reduced through the utilization of the RF shield 632. The RF shield 632 is sized such that when the reader 604 is brought into proper position with an intended target sample holding unit—the central sample holding unit 658 in the present example—the RF transceiver antenna 620 of the reader 604 and the RFID tag 670 of the target sample holding unit 658 are both located within the interior space 636 established by the RF shield 632. The RF shield 632 has the effect of isolating the RF transceiver antenna 620 from the RFID tags of any neighboring sample holding units (e.g., RFID tags 666 and particularly 674). In a sense, the RF shield 632 “hides” the RFID tags of neighboring sample holding units from view, thereby providing enhanced positional selectivity. By way of example, FIG. 6 illustrates a desired wireless link or communication 678 established between the RF transceiver antenna 620 and the RFID tag 670 of the central sample holding unit 658 and an undesired wireless link or communication 682 potentially established between the RF transceiver antenna 620 and the RFID tag 674 of the rightmost sample holding unit 662. The isolation provided by the RF shield 632 prevents the undesired wireless link 678, or greatly impedes successful communication via the undesired wireless link 678.

In the example specifically given in FIG. 6, when the reader 604 is lowered into place toward the central sample holding unit 658, the axial (e.g., vertical) dimension of the RF shield 632 is large enough to completely enshroud the central sample holding unit 658, such that the open end 640 of the RF shield 632 is located at or near the bottom of the central sample holding unit 658. It will be understood, however, that the length of the lateral wall(s) 644 of the RF shield 632 need not be so great as to extend along the full height of the central sample holding unit 658. The RF shield 632 need only be sized so as to effectively isolate the RF transceiver antenna 620 from the RFID tags of neighboring sample holding units such as the RFID tag 674 of the rightmost sample holding unit 662. In this regard, it will be understood that the sample holding units 654, 658 and 662 illustrated in FIG. 6 may represent just the upper regions of respective sample containers. In cases where the positions of RFID tags of adjacent sample holding units are inconsistent as to height or depth, however, the complete encasing of a target sample holding unit from neighboring sample holding units may be desirable.

While FIG. 6 illustrates an example in which adjacent sample holding units 654, 658 and 662 are physically separated from each other by gaps or spacings 686, it can be appreciated that adjacent sample holding units 654, 658 and 662 need only be demarcated by grooves or channels. That is, the spacing 686 between adjacent sample holding units 654, 658 and 662 do not need to extend for the full height of the sample holding units 654, 658 and 662. It may be sufficient for the spacing 686 to extend from the top surfaces of the sample holding units 654, 658 and 662 and partially down the sides of the sample holding units 654, 658 and 662. Moreover, the spacing 686 may represent the distance between the upper regions of adjacent sample containers, above the sample holder 650. Generally, the size of gaps or grooves 686 between the sample holding units 654, 658 and 662 need only be sufficient to receive the RF shield 632 to the extent needed for effective RF signal isolation.

FIG. 7 schematically illustrates an RFID apparatus or system 700 according to another implementation that provides an RF shield. Many components and features of the RFID apparatus 700 illustrated in FIG. 7 may generally be similar to those of the RFID apparatus 600 illustrated in FIG. 6. Accordingly, a full description of such components and features will not be repeated in conjunction with the description pertaining to FIG. 7. In implementations such as illustrated in FIG. 6, the RF shield may be considered as being associated with a reader. In implementations such as illustrated in FIG. 7, the RF shield may be considered as being associated with sample containers or a sample holding assembly, or as being a component separate from both a reader and sample containers or a sample holding assembly.

As illustrated in FIG. 7, the RFID apparatus 700 includes a reader 704. The reader 704 includes a main body 708 and an RF transceiver antenna 620. The reader 704 itself does not include an RF shield but in other aspects may be similar to the reader 604 illustrated in FIG. 6. The RFID apparatus 700 further includes an RF shielding structure 732 that includes a plurality of individual RF-shielding wells or RF shields 734. The RF shielding structure 732 may serve as a sample holder in which each well 734 contains an individual sample holding unit 654, 658 or 662, or may be integrated with (or mounted to) a sample holder 750 in which each compartment or sample holding module is protected by RF shielding material of the RF shielding structure 732. As shown by example in FIG. 7, the RF shielding structure 732 may include a plurality of generally vertically oriented walls 744. Each wall 744 extends from a gap or groove 786 between adjacent sample holding units 654, 658 and 662 and for a distance beyond the expected height of the sample holding units 654, 658 and 662. The walls 744 may be constructed from any material suitable for impeding the transmission of RF energy through the walls 744, as described above. The walls 744 may integrally extend from or otherwise be supported by a base 746. The base 746 may be integrally part of either the RF shielding structure 732 or a sample holder 750. The base 746 may also be constructed from RF-shielding material if RF shielding at the undersides of the sample holding units 654, 658 and 662 is desired, or if such a configuration facilitates fabrication. The walls 744 may be shaped such that each well 734 is generally cylindrical or polygonal as needed to accommodate the shapes of the sample holding units 654, 658 and 662. Each resulting well 734 defines an interior space 736 generally between the base 746 (or a sample holding unit residing in the well 734) and an open end 740 of the well 734. The open ends 740 of the wells 734 are located at a large enough distance above the expected heights of the sample holding units 654, 658 and 662 so as to effectively isolate the wells 734, and any sample holding units 654, 658 and 662 residing in the wells 734, from each other while the reader 704 is communicating with a target RFID tag.

In practice, individual sample holding units 654, 658 and 662 such as sample containers are placed in respective wells 734 of the RF shielding structure 732. Alternatively, a sample holder 750 containing individual sample holding units 654, 658 and 662 is interfaced with the RF shielding structure 732 such that each sample holding unit 654, 658 and 662 is positioned within a corresponding well 734. In either case, the RFID tag 666, 670 and 674 of each respective sample holding unit 654, 658 and 662 is positioned in the interior space 736 of a corresponding well 734. A target sample holding unit—the central sample holding unit 658 in the present example—is selected, and the reader 704 is moved to the target sample holding unit 658. The reader 704 is lowered toward the target sample holding unit 658. The reader 704 is lowered far enough not only to establish a good communication link 678 between the RF transceiver antenna 620 and the RFID tag 670 of the target sample holding unit 658, but also to position the RF transceiver antenna 620 within the well 734 of the target sample holding unit 658 and thus effectively isolate the RF transceiver antenna 620 from the RFID tags of any neighboring sample holding units.

FIG. 7 illustrates an arrangement of sample holding units 654, 658 and 662 analogous to the arrangement described above and illustrated in FIG. 6, in which the RFID tags 666, 670 and 674 of the respective sample holding units 654, 658 and 662 are not consistently positioned. The shielding effect of the implementation illustrated in FIG. 7 is likewise analogous to that of the implementation illustrated in FIG. 6. The RF shielding structure 732 promotes interference-free communication 678 between the RF transceiver antenna 620 and the RFID tag 670 of the target sample holding unit 658, and prevents or significantly impedes communication 682 between the RF transceiver antenna 620 and the RFID tag of neighboring sample holding units such as the rightmost sample holding unit 662.

In other implementations, features or elements of the RF shielding components illustrated in FIGS. 6 and 7 may be combined. For example, a reader 604 may be provided with an RF shield 632 as shown in FIG. 6, and a sample holder 750 or sample holding units 654, 658 and 662 may be provided with RF shields or wells 734 as shown in FIG. 7. The diameter of the RF shield 632 of FIG. 6 may differ slightly from the diameters of the RF shields 734 of FIG. 7. By such a configuration, upon moving the RF shield 632 into proper position over a target sample holding unit, a lower portion of the RF shield 632 may overlap with an upper portion of the RF shield 734 surrounding the target RFID tag to create a fully enclosed RF shielding interior space 636 or 736.

In some implementations, when moving an RFID tag reader into proper position over a target sample holding unit, it is possible for the open end of the RF shield provided with the reader to come into contact with a surface, such as a base supporting sample holding units, a portion of the target sample holding unit itself, or the bottom of the gap or groove surrounding the target sample holding unit. Such contact may cause misalignment of or damage to components and/or reduce the effectiveness of the isolation provided by the RF shield.

FIG. 8 illustrates two examples of such a situation. In FIG. 8, two sample containers 854 and 858 are supported in a sample holding tray 850. In these examples, similar to the example illustrated in FIG. 1, each sample container 854 and 858 includes an open-topped container structure 812 that includes a sidewall 814. Each sample container 854 and 858 is sealed at its open top 818 with a closure member 824 that is retained by an apertured end member or cap 821. In each example, an RFID reader device 804, including a main body 808, RF transceiver antenna 820 and RF shield 832 with an open end 840, has been moved into position over the sample container 854 or 858. In the case of the left sample container 854, the diameter of its open top 840 (as well as its closure member 824 and end member 821) is significantly narrower than the diameter of its sidewall 814, such that the sidewall 814 of the left sample container 854 has a protruding shoulder region 815. Thus, in the case of the left sample container 854, it is possible for the open end 840 of the RF shield 832 to come into contact with the shoulder 815 during positioning of the reader 804. In the case of the right sample container 858, the diameter of its open top 840 (or its closure member 824 and end member 821) is substantially the same as the diameter of its sidewall 814, such that the sidewall 814 of the right sample container 858 has a non-obstructing shoulder region 817. Thus, in the case of the right sample container 858, the RF shield 832 may be lowered farther down the side of the sample container 858, bypassing the shoulder region 817, but it is nonetheless possible for the RF shield 832 to come into contact with the top of the sample holding tray 850 (or the bottom of a gap surrounding the sample container 858 if such a gap is provided) during positioning of the reader 804. In the case of either example, if the sample containers 854 and 858 are closely positioned to each other in the sample holding tray 850, it is possible for the RF shield 832 to come into contact with a neighboring sample container while being moved into position over the target sample container.

To prevent the RF shield 832 or its associated reader 804 from becoming misaligned or damaged from impacting an obstruction, and to ensure the effectiveness of RF isolation in such case, the RF shield 832 may be connected to the main body 808 of the reader 804 so as to be movable (e.g., retractable) relative to the reader 804, as depicted by the arrow 882 in FIG. 8. Any suitable mechanical solution may be implemented to render the RF shield 832 retractable. For example, as illustrated with the left sample container 854 in FIG. 8, the RF shield 832 may include generally horizontal arms or legs 884 that are movable in generally vertical slots or tracks 886 provided at the side of the reader 804. As another example, as illustrated with the right sample container 858, the RF shield 832 may include concentric telescoping sections 888 and 890, with at least one of the sections being movable relative to the other(s), to enable retracting movement upon encountering an obstruction. In some implementations, the retractive movement of the RF shield 832 may be biased by any suitable spring-loading means. For example, the RF shield 832 may be mounted to the body 808 of the reader 804 with the use of one or more springs (not shown).

Referring now to FIGS. 9 and 10, another example of an RFID tag 900 is illustrated. The RFID tag 900 may be utilized in conjunction with any of the implementations described in this disclosure. Referring to the top planar view of FIG. 9, the RFID tag 900 includes a microchip 910 attached to a substrate 916. As appreciated by persons skilled in the art, the microchip 910 may include circuitry that implements various functions such as, for example, memory, power generation, and/or control. In this example, the RFID tag 900 has a built-in antenna design. Specifically, the microchip 910 communicates with an antenna 918 that is also attached to the same surface of the substrate 916. The antenna 918 may be formed as a planar (or substantially flat) coil surrounding the microchip 910 along several turns, such that the length of the antenna 918 is distributed over a large portion of the illustrated surface of the substrate 916. The elongate structure (e.g., wire or strip) employed to form the antenna 918 may be circular or planar in cross-section. While in the illustrated example the coil of the antenna 918 is configured as contiguous rectilinear loops with several straight sections adjoined at corners, it will be understood that the coil may have any other suitable configuration. For example, the coil may be configured so as to spiral outwardly from the microchip 910. The foregoing components of the RFID tag 900 may be disposed on, or embedded in, an additional element such as a protective base or casing 922. The base or casing 922 may be fabricated from any suitable material that may provide thermal, moisture, ultraviolet (UV), impact and/or electrical isolation or protection. For example, the base or casing 922 may be constructed from various types of plastics. The base or casing 922 may be circular as illustrated or may have any other suitable shape. The side elevation view of FIG. 10 illustrates the example in which the protective element 922 is a casing and the components of the RFID tag 900 are embedded in the protective casing 922.

In one non-limiting example, one or more sides 926 of the substrate 916 have a length ranging from about 0.5 to about 10 mm, the width of the elongate structure forming the antenna 918 ranges from about 5 to about 50 μm, and the gap 930 between each adjacent section of the antenna 918 ranges from about 2 to about 8 μm. In one particular example, the length of each side 926 of the substrate 916 is about 2.5 mm, the width of the elongate structure forming the antenna 918 is about 14 μm, and the gap 930 between each adjacent section of the antenna 918 is about 4 μm. In one implementation, the RFID tag 900 may be provided as a Coil-on-Chip™ device commercially available from Maxell Corporation of America, Fair Lawn, N.J.

FIG. 11 is a top plan view of an arrangement 1100 of sample containers for which respective RFID tags 900 of the type illustrated in FIGS. 9 and 10 are provided. Specifically, the respective RFID tags 900 are mounted on respective upper structures 1104 of the sample containers. The upper structures 1104 may, for example, correspond to or be part of the end member or cap 120 or 821 illustrated in FIG. 1 or 8. Alternatively, as described further below, the upper structures 1104 may be additional components that are mounted to the sample containers. Each upper structure 1104 may include an aperture 1108 for providing access to the sample container. Unlike the implementations illustrated in FIGS. 1 and 2, the RFID tag 900 is not configured so as to be coaxially disposed about the central axis of the sample container, or around the aperture 1108 of the upper structure 1104. Instead, as illustrated in FIG. 11, the RFID tag 900, including its antenna 918 (FIG. 9), is positioned off-center relative to the central axis and the aperture 1108.

In the ideal arrangement 1100 illustrated in FIG. 11, the RFID tags 900 provided with the array of sample containers are all oriented uniformly relative to each other. In such a case, the off-center orientations of the RFID tags 900 may not be expected to cause any difficulties in the operation of an RFID tag reader. Each RFID tag 900 is spaced at an appreciable distance from neighboring RFID tags 900, and the design and operation of the RFID tag reader could be implemented in consideration of the uniform orientation illustrated in FIG. 11. On the other hand, unless steps are taken to control the orientation of the RFID tags 900 (or the upper structures 1104 to which they are mounted), the uniform arrangement 1100 is not ensured. For example, FIG. 12 is a top plan view of an arrangement 1200 of sample containers in which the RFID tags 900 are not uniformly oriented relative to each other. It can be seen in FIG. 12 that some of the neighboring RFID tags 900 are positioned quite close together. In such a situation, problems associated with the proper interaction between the RFID tag reader and a target RFID tag may arise, such as described above in conjunction with FIGS. 6 and 7. Accordingly, the provision of RF shielding devices 632 or 732 such as described above in conjunction with FIGS. 6-8 may be useful in implementations that employ off-center RFID tags 900.

FIG. 13 illustrates an example of a sample container 1300 such as a vial according to another implementation. The sample container 1300 includes an open-topped container structure 1312 that includes a sidewall 1314 and a closed bottom end 1316. The sample container 1300 may be sealed at its open top 1318 with a closure member 1324 that is retained by an end member or cap 1321. The cap 1321 may have an aperture 1322 to provide access to the interior of the container structure 1312. Access may be effected by puncturing the closure member 1324 if the closure member 1324 is provided. In this implementation, the sample container 1300 includes an additional end member or cap 1342 that may be mounted onto the first cap 1321. The second cap 1342 may be configured to be secured to the first cap 1321 by any suitable means such as, for example, press-on fitting or threaded engagement. In implementations where the first cap 1321 has an aperture 1322, the second cap 1342 may likewise have an aperture 1343 generally aligned with the aperture 1322. The second cap 1342 may be employed to provide additional protection for the sample container 1300, and may be utilized in conjunction with any of the implementations described in this disclosure. In addition, the second cap 1342 may serve as a mounting location for an RFID tag. For example, a recess 1386 may be formed in the second cap 1342, and the RFID tag 900 illustrated in FIGS. 9 and 10 may be positioned in the recess 1386 in off-center or radially offset relation to the central longitudinal axis of the sample container 1300. For these purposes, the second cap 1342 may be fabricated from any suitable material such as, for example, plastic. The second cap 1342 enables the RFID tag 900 to be easily removed from the sample container 1300, and thus easily reprogrammed apart from the sample container 1300 and reused with the same sample container 1300 or a different sample container.

From the foregoing, it may be seen that implementations disclosed herein can provide advantages over barcode technology and other previous techniques for identifying samples. For example, the RF transceiver antenna of a reader does not require a line of sight with an RFID tag in order to detect the information stored by the RFID tag, whereas barcode scanners need to “see” a barcode in order to read it. Moreover, RFID tags are insensitive to orientation with a reader, whereas a barcode must be optically aligned with a barcode scanner. RFID tags allow for individual sample containers to have unique identifiers and can quickly identify several individual samples either simultaneously or sequentially, whereas the typical barcode provides only an identification of a manufacturer and product. In closely arranged groupings of sample containers, an RF transceiver antenna and a selected RFID tag can communicate without interference or error due to the proximity of other tagged sample containers. RFID tags are much more robust than barcode labels, and have much longer useful lives. RFID tags are much more resistant to potential laboratory mishaps such as smearing, solvent exposure, abrasion, obstruction, and the like. RFID tags are programmable and may further be reprogrammable. The same RFID tag can be recoded with new information when desired. An RFID tag in many implementations can store much more information than is possible with a barcode label. The RFID tags in combination with RF-based readers may be easily integrated into existing sample handling systems without unduly affecting any other pre-existing, more conventional operations of such systems. Because an RF interrogation element such as an antenna can be easily incorporated into a moving component such as a device or assembly supporting a sample conduit, the implementations disclosed herein introduce the concept of moving the RF interrogation element to sample containers. Individual sample containers do not need to be moved to reading or scanning stations or the like.

Moreover, it may be seen that implementations disclosed herein may eliminate or significantly reduce the occurrence of cross-reading among closely spaced RFID tags of separately identifiable objects such as sample containers, particularly when the positions of RFID tags relative to their objects are not well-controlled.

It will be understood that various aspects or details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation-the invention being defined by the claims. 

1. A radio frequency identification (RFID) reader, comprising: a body including a proximal end region; an RF transceiver antenna mounted to the body at the proximal end region; and an RF shield mounted to the body and extending out from the body beyond the proximal end region to an open end of the RF shield, the RF shield defining an interior space between the body and the open end, wherein the antenna is surrounded by the RF shield.
 2. The reader of claim 1, comprising a sample probe device, the sample probe device including the body and a sample probe.
 3. The reader of claim 1, further comprising a robotic device communicating with the body for moving the body.
 4. The reader of claim 1, wherein at least a portion of the RF shield is movable relative to the body.
 5. A sample holder, comprising: an RF shield including a plurality of walls defining a plurality of interior spaces; and a sample container positioned in at least one of the interior spaces, the sample container including a radio frequency identification (RFID) tag surrounded by one or more of the walls.
 6. The sample holder of claim 5, wherein the sample container includes a first structure including an open end enclosing a container interior, and a second structure mounted to the first structure at the open end, and the RFID tag is positioned near the open end.
 7. The sample holder of claim 6, wherein the RFID tag is attached to the first structure.
 8. The sample holder of claim 6, wherein the RFID tag is attached to the second structure.
 9. The sample holder of claim 6, wherein the RFID tag is positioned in off-center relation to a central axis passing through the open end.
 10. The sample holder of claim 6, wherein at least a portion of the RFID tag is positioned coaxially about a central axis passing through the open end.
 11. A radio frequency identification (RFID) apparatus, comprising: an RFID reader including an RF transceiver antenna; a sample container including an RFID tag; and an RF shield defining an interior space between the reader and the container, wherein the antenna and the RFID tag are surrounded by the RF shield.
 12. The apparatus of claim 11, wherein the RF shield is mounted to the reader.
 13. The apparatus of claim 11, wherein the sample container is positioned in the interior space.
 14. A method for identifying an object, comprising: moving a reader, including a radio frequency (RF) transceiver antenna, into proximity with a sample container whereby the antenna can communicate with a radio frequency identification (RFID) tag of the sample container; and surrounding the antenna and the RFID tag with an RF shield such that the antenna and RFID tag are isolated from an environment external to the RF shield.
 15. The method of claim 14, wherein the RF shield is attached to the reader and defines an interior space in which the antenna is located, and surrounding includes moving the reader toward the sample container such that the RFID tag becomes located within the interior space.
 16. The method of claim 14, wherein the RFID tag is located in an interior space defined by the RF shield, and surrounding includes moving the reader toward the sample container such that the antenna becomes located within the interior space.
 17. The method of claim 14, further comprising using the antenna to read a code stored by the RFID tag whereby the sample container or a sample contained in the sample container can be identified
 18. The method of claim 17 further comprising, after reading the code, associating the code with information relating to the identified sample container or sample.
 19. The method of claim 14, further comprising using the antenna to determine whether the sample container is present at a selected location.
 20. The method of claim 14, wherein the sample container is a target sample container positioned proximate to one or more neighboring sample containers including respective RFID tags, and the method further comprises establishing communication between the antenna and the RFID tag of the target sample container without interference from RFID tags of the one or more neighboring sample containers.
 21. A sample container, comprising: a container structure extending along a central axis, the container structure enclosing an interior and including an open end; a first cap mounted to the container structure at the open end and having a first aperture located at the central axis; a second cap mounted to the first cap and having a second aperture aligned with the first aperture along the central axis; and an RFID tag mounted at the second cap in off-center relation to the central axis.
 22. The container of claim 21, further including a closure member mounted at the open end, whereby the interior is isolated from an environment external to the container structure and the first and second apertures provide access to the closure member. 